Chronic renal failure (CRF), or the more recently coined term “chronic kidney disease” (CKD), is a progressive deterioration and loss of renal function typically over a relatively long time period such as months to years. There are five recognized stages of CRF (CKD) based primarily on glomerular filtration rate (GFR). Although a GFR of greater than 90 mL/min/1.73 m2 (“90 mL/min”) is considered normal, an individual with a GFR greater than 90 ml/min may nonetheless be classified as stage 1 CRF if he/she has experienced some form of kidney damage as evidenced by abnormal blood or urine markers of kidney damage (e.g., increased creatinine levels), abnormal imaging results, and/or has one or more risk factors (e.g., proteinuria, diabetes, high blood pressure, family history of CRF, cardiovascular disease). Stage 2 CRF (CKD) is characterized by a relatively mild reduction in GFR to 60-89 mL/min/1.73 m2 (“60-89 mL/min”) along with any of the other risk factors of stage 1, stage 3 by a GFR of 30-59 mL/min, stage 4 by a GFR of 15-29 mL/min, and stage 5 by a GFR of less than 15 mL/min. Stage 5 CRF is also referred to as end-stage renal disease (ESRD), and such patients will not survive long, particularly as the GFR approaches 5-10 ml/min, without some form of renal replacement therapy, such as dialysis or kidney transplantation.
Currently, there is no approved therapy to reverse the progression of CRF from stage 1 to stage 5 (ESRD), although early diagnosis along with current therapy may delay progression to ESRD and the need for renal replacement therapy. Both dialysis and kidney transplantation can present a variety of risks or side effects to the patient, such as infection, rejection of organ transplant, and fatigue with treatment, which can ultimately lead to patient mortality.
In the United States, billions of dollars are currently necessary to provide renal replacement therapy, and such costs are expected to increase. Accordingly, delaying the need to provide renal replacement therapy, including lengthening the time between dialysis treatments of currently diagnosed ESRD patients, would both provide a significant benefit to a CRF patient's quality of life and also significantly lower costs of treatment by decreasing the number of dialysis sessions and decreasing overall the number of kidney transplants that need to be performed.
In the current circumstances, there is a clear need for improved methods for diagnosis and treatment of chronic renal failure.